The science we build on.
Long-form essays on sleep physiology, heart rate variability calibration, biological age methods, wearable accuracy, and N=1 trial methodology. Every citation traceable. Written for people who want to read the actual paper, not just the headline.
Sleep Regularity Index: The Score That Predicts Mortality Better Than Duration
The Phillips Sleep Regularity Index outperforms total sleep duration as a predictor of mortality, HbA1c, and depression. Here is how it is computed and why most apps ignore it.
Sleep Apnea Screening From Your Wearable: T90 and ODI Explained
One in five men have undiagnosed sleep apnea. T90 and ODI thresholds derived from overnight SpO2 can flag risk before a sleep study. Here is how.
Nocturnal Heart Rate Dip: The Recovery Marker Most People Miss
Healthy adults' heart rate drops 10-25% during sleep. A blunted dip predicts cardiovascular mortality independently. Here is how to compute it from any wearable.
N=1 Trials: The Science Behind Personal Health Protocols
Population trials tell you what works on average. N=1 trials tell you what works for YOU. Here is the methodology, the statistics, and why no consumer app does it properly.
ApoB vs LDL-C: The Cholesterol Number That Predicts Heart Attacks
LDL-C estimates cholesterol carried. ApoB counts the actual atherogenic particles. Here is why ApoB outperforms LDL-C for cardiovascular risk, and when they diverge.
HRV Calibration: Why Your Recovery Score Is Wrong
Heart rate variability swings 15-25% day-to-day even at perfect health. Here is why population HRV norms mislead, and how to build the personal baseline that does not.
The Three-Layer Sleep Readiness Score That Actually Works
WHOOP says 64. Apple says 87. Oura sits between. Here is why single-device readiness scores mislead, and the three layers required to fix them.
Biological Age Tests Compared: PhenoAge, GrimAge, DunedinPACE, Horvath
Four biological age methods, four different jobs. A practitioner-grade comparison of PhenoAge, GrimAge, DunedinPACE, and Horvath: what each measures, accuracy, cost.
Morning Sunlight: The Free Intervention That Outperforms Most Supplements
Ten minutes of outdoor light within 30 minutes of waking anchors cortisol, improves nocturnal sleep, and entrains your circadian system. The biology and the protocol.
Whoop vs Oura vs Apple Watch: HRV Accuracy Compared (2026)
A practitioner-grade comparison of HRV accuracy across the three most-used wearables, with the validation data, the methodological caveats, and a use-case verdict.
Research-first, citation-grade.
VITA Research compiles long-form summaries of the primary literature behind the metrics our app surfaces — sleep physiology, HRV calibration, biological age methods, wearable accuracy, N=1 trial methodology. Every primary claim is anchored to a peer-reviewed paper. Where commercial or manufacturer-funded validation is used, it is flagged. No supplement marketing, no diagnostic claims.
If you find a citation we misread or a study we missed, write to us — we update articles when the underlying literature changes.